The invention relates to paint and coating material systems and to their use for preparing paint and coating materials.
In the field of pigmented liquid paint and coating materials, the use of aqueous or solvent dispersions of pigments and fillers, and binders, in particular, is known. Examples of suitable pigments and fillers include organic and inorganic colour pigments, i.e. white, black and chromatic pigments. Binders used include both organic and inorganic, but generally organic, network-forming or film-forming polymers which may be present in emulsified, dispersed or dissolved state in a paint material.
Pigmented paint and coating materials generally include further additives and, possibly, further solvents.
The pigmented aqueous paint and coating materials are generally prepared by dispersing the pigments and fillers in the presence of water and, where appropriate, further additions. Dispersion comprises the deaggregation or deagglomeration of the pigment and filler particles, which in their dry powder form or aqueous presscake form are in a state of high physical aggregation on account of their preparation process, and also the physical stabilization of the pigments or fillers finely distributed in this way, by means of suitable additives such as dispersants, emulsifiers or thickeners, for example, in order to achieve the desired properties of the finished liquid products (paints), such as storage stability, hiding power and whiteness (lightening), colour strength, shade and brilliance, etc. Consequently, the preparation of the aqueous paints and coating materials always involves the high energy input which, industrially, can be effected only through the use of, for example, wet comminuting machines such as dissolvers, attritors, ball mills, rotor-stator mills, stirred bead mills, high-pressure homogenises and so on.
For this reason, the dispersions can be prepared only on the industrial scale; and it is only on that scale that industrial equipment is available on the market and can be used economically. In the past, until the present day, a consequence of this has been that paint and coating materials have been obtainable exclusively as ready-formulated liquid preparations. This applies both to products intended for industrial use and to those intended for use closer to the consumer.
As well as the advantages of the ease of handling of the liquid preparations matched in this way to the use in question, however, there are considerable disadvantages. For instance, the relatively large volume of the paint and coating materials owing to the water and possibly solvents they contain (in total up to 90%; e.g. high-grade white interior paint: from 30 to 50% by volume water) is disadvantageous since it entails great expenditure as regards the nature and size of the means of packaging (tin cans, plastic buckets and drums) and as regards the storage and transport.
Moreover, the aqueous preparations often possess inadequate keeping properties and storage properties owing to:
Mould and bacterial infestation, necessitating the use of high quantities of biocide;
Sedimentation or reagglomeration of the pigments or fillers or thickening of the liquid phase, generally necessitating stirring of the products before use;
Drying (including drying-out) of the products in and to the container, always associated with noticeable quality detractions in the products, such as bittyness in the paint or in the coating, for example.
Often, a large amount of agents for improving the antifreeze qualities and resistance to drying out, such as solvents, especially glycols, polyglycols and so on, is necessary; however, such agents bring with them grave disadvantages as regards the very properties of the product, such as the microbiological keeping properties and the tackiness of the products following application, for example. Furthermore, it is nowadays becoming more and more difficult to find suitable preservatives for aqueous preparations containing, for example, glycol or polyglycol that are able to counter the increasing adaptation of microorganisms and are also environmentally acceptable.
Grave environmental disadvantages of liquid preparations relate in particular to the disposal of leftover products, product wastes and containers at all stages of the product life cycle. This applies to the production process of the aqueous preparations, storage and container filling, selling, storage and use in households and industry, and in the trade. As far as aqueous paint materials are concerned, for instance, it is easy to estimate that in private households alone the amount of leftover products and product wastes is very large. Disposing of such leftovers and wastes is known to be expensive. It is therefore an object of the present invention to provide a paint and coating material system with which the above disadvantages can be largely avoided.
A paint and coating material system has now been found comprising
a) at least one solids component comprising at least one organic or inorganic white, black or chromatic pigment, organic or inorganic fillers, or mixtures thereof, and
b) at least one binder component, characterized in that the components of the system in water, with a specific energy input of less than 150 J/cm3, based on the sum of the volumes of the components and water, produce an aqueous dispersion having a particle size of  less than 60 xcexcm, preferably less than 40 xcexcm (determined in accordance with ISO 1524: 1983).